I checked the coredumps and while they are (of course) not too helpful it pretty much looks like an infinite recursion. Did get the coredumps out of the server or client? And most importantly: can you at least loosely relate them to any action in the game?

And unfortunately, it seems totally random when it occurs, but it occurs quite often as you can see... We player deathmatch on 580plaza, doombank, airport and two others, and it occured in all of them. Using nvidia-drivers 378.13..

If you have a build with debug symbols enabled, I could try that to see if the crash dump makes more sense :)